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New Scientist Live

Counting down

By Fred Pearce

THIS month, somewhere in the world—it could be in a London maternity
ward, but more likely in a São Paolo favela or a Calcutta
slum—the 6-billionth member of the human race will be born. The UN will
officially recognise his or her birthday on 12 October.

Only 12 years have passed since we hit the 5-billion mark, so the event has
been greeted with portentous warnings of a “population time bomb” and a
“demographic disaster”. But delve behind the words of the doom-mongers, say some
demographers, and you’ll find evidence that in the not-too-distant future, the
world population may actually start to shrink.

According to this very different picture, the world’s population will peak
some time in the 21st century, then start falling. So while today’s youth are
exhorted to have fewer children, their grandchildren may be actively encouraged
to go forth and multiply.

“Over the past five years, fertility has declined in all major parts of the
world,” says one of the heretics, Wolfgang Lutz, head of population research at
the International Institute for Applied Systems Analysis in Laxenburg, Austria.
“All changes point to lower population forecasts.” And on his most recent
forecasts, the upward path of population growth, which has been accelerating
ever since the Black Death killed as much as a third of Europe’s population in
the 14th century, will stall and go into reverse in about 70 years.

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The signs of a possible decline in the human population have been building
for several years now. In the 1950s, women around the world had 5 children on
average. Now women have just 2.7 children each. During the past decade, the
annual increase in the head count has fallen from 90 million to 78 million. And
in one sector of the population, absolute numbers are falling. In 1990, there
were 623 million under-fives. By 1995, there were only 614 million under-fives.
It could be the start of a trend that will spread right across the age
spectrum.

Demographers had predicted a downturn. But it is happening much faster and
more widely than they anticipated. Twice in the past three years, the UN’s
statisticians have lowered their projections of future populations. On the
second occasion, late last year, they postponed by four months the “six-billion
day” and reduced their forecast of the world population in 2050 by half a
billion, from 9.4 billion to 8.9 billion.

The main reason for these changes is the dramatic fall in fertility rates,
particularly in the developing world. Across Africa and Asia, hundreds of
millions of people are confounding predictions by reducing family sizes. It used
to be said that, without the Draconian imposition of birth control, only
countries with rising prosperity and increasingly literate and urban populations
could go through what demographers call the demographic transition—the
switch to smaller families and stable populations.

But in the 1990s, a number of countries have disproved this. Bangladesh, once
in the world’s demographic doghouse, has cut its fertility rate from 6.2
children per woman to 3.4 in a decade, thanks to contraception, and despite
extreme poverty and illiteracy. Fertility rates in many African countries,
though still very high, are falling fast as contraceptive use grows there as
well.

Lester Brown, director of the Worldwatch Institute in Washington DC and
author of a new study on world population, Beyond Malthus, is well
known for his apocalyptic visions of an overpopulated future. But even he
concedes: “Demographers have been surprised again and again by the rapid decline
in the number of children couples choose to bear throughout the world.”

But there is also a dark side to the population slow-down. In sub-Saharan
Africa death rates are rising due to the spread of HIV. In some countries, a
quarter of the adult population is infected. Last year, the US Census Bureau
calculated life expectancy in Botswana had fallen from 62 years to 40 years, and
in Zimbabwe from 61 to 39(New Scientist, 17 October 1998, p 12). In
one of the most eloquent testimonies to the social impact of AIDS in Africa, the
UN population agency in Zimbabwe this year limited the number of funerals its
staff can attend in work time to one a week.

Says Brown: “Tragically, the world is divided into two parts: one where
population growth is slowing as fertility falls, and one where population growth
is slowing as mortality rises.”

The prognosis for the AIDS pandemic is unclear: in the next twenty years much
will depend on how quickly science can supply affordable and effective vaccines
to the developing world. However, fertility rates may be more predictable.
According to the UN’s population division in New York, fertility rates are now
below the long-term replacement level of 2.1 in 61 countries, including most of
Europe, the Caribbean and eastern Asia, including China. American women have 2
children on average, British women 1.7 and in Catholic countries such as Italy
and Spain, the figure is as low as 1.2 children.

Some senior UN demographers think this pattern is unlikely to continue. They
say fertility rates will eventually return to higher levels. However, they fail
to provide a detailed explanation of why they believe this, although some note
that many modern women may simply be postponing having children rather than not
having any at all. Based on these assumptions, the UN predicts that some time
towards the end of the 21st century, the world’s population will stabilise at
between 10 or 11 billion.

But Warren Robinson, at the Pennsylvania State University, says: “It requires
a leap of faith to assume that replacement-level fertility will be the average
procreational goal of all couples in the world for generations to come.”

And the UN’s own shorter-term predictions seem to cast doubt on the 10 to 11
billion figure. World Population Prospects: The 1998 Revision suggests
that 18 countries, including Russia and Japan, will lose more than 15 per cent
of their population by 2050. Revisions of these estimates provide further
evidence of a population decline. In the space of just two years, Bulgaria’s
predicted 2050 population was adjusted from 7.8 million to 6.7 million. Its
population is currently 8.3 million.

Nafis Sadik, executive director of the UN Population Fund, admitted last
week: “No country in history has ever succeeded in raising birth rates over a
long period once they have started to decline.” Lutz predicts that around 2070,
the world’s overall population will begin to fall. Many UN demographers quietly
agree. And less trumpeted is the UN’s low projection(see Graph), the latest of
which makes sobering reading. It predicts that the world’s population will peak
in 2040 at around 7.7 billion people and then go into a long-term decline. By
2100, it could be back below today’s figure of six billion and by 2150 the
projection is for just 3.6 billion people.

The 20th century gave us a world population explosion. It looks increasingly
as if the 21st century may see the beginnings of a population implosion. The
most immediate impact of these demographic changes will be an ageing
population.

China, with its policy of one-child families adopted in the 1980s, has a head
start in the ageing process. Current trends suggest that by 2030, it will have
the oldest population of any society anywhere in the world ever. By 2050, the
country will have 150 million people over the age of 75.

Already in Europe around one in five of the population is over 60. But the
population will get older. Lutz suggests that by the end of the next century,
half of Europe’s population could be over 60. The economic impact will
enormous.

Some futurists think new healthcare technology and creative approaches to
leisure will more than make up for these changes. But many fear that such
rampant ageing, combined with a decline in the overall population, will sap
nations’ energy as well as social services, starving businesses of innovative
ideas and dynamism, and creating a grey, conformist society. In other words, the
decline and fall of the human empire.